Section 9.2 of IEEE 802-2001 specification describes the 48-bit universal LAN MAC address, Media Access Control address (Hardware Network Address). The first 24 bits is the Organization Unique Identifier (OUI) if the 2nd LSB is set to 0.

- If b1 is set to 0 then the MAC address is an individual address.
- If b1 is set to 1 then the MAC address is identify as one or more destination address, broadcast address.
- If b2 is set to 0 then the MAC address is Globally unique (OUI enforced).
- If b2 is set to 1 then the MAC address is locally administered.
Examples of locally administered MAC, “x” is any hex digit:
x2:xx:xx:xx:xx:xx
x6:xx:xx:xx:xx:xx
xA:xx:xx:xx:xx:xx
xE:xx:xx:xx:xx:xx